Alloys



Patented May 9, 1944 UNITED STATES PATENT OFFICE ALLOYS Reginald S. Dean and Clarence '1. Anderson, Salt Lake City, Utah, assignors to Chicago Developinlinegtigompany, Chicago, 11]., a corporation of No Drawing. Application October 20, 1941, Serial No. 415,768

6 Claims. (01. 75-134) Our invention relates to the preparation of alloys having good corrosion resistance.

The alloys to which our invention relates comprise, in their broadest aspects, alloys containing from to 75% manganese, from 5% to 25% chromium, and from 20% to 90% copper, the total of the manganese, chromium and copper constituting substantially 100%. The preferred embodiments of our invention comprise alloys containing from about 10% to about 20% manganese, from about 10% to about 20% chromium, balance substantially all copper.

, The following examples are illustrative of alloys falling within the scope of our invention. It will be understood that these examples are in no wise limitative of the full scope of the invention and that various changes may be made with respect to proportions of alloying elements, treatment of the alloys, and the like, without departing from the spiritof our invention.

Example I An alloy was prepared containing 80% copper, 10% manganese, and 10% chromium, said alloy being prepared from highly pure metals, particularly preferred being those produced electrolyti-' cally. The resulting alloy, after cold working and annealing at 750 degrees 0., was very soft and ductile and had a tensile strength of approximately 40,000 pounds per square inch. On cold working, the alloy undergoes an unusual amount of work hardening, reaching a tensile strength of approximately 115,000 pounds per square inch in a fully cold worked 'state. The coeflicient of linear expansion of the alloy was 1417x10 cm./cm./ C. and the electrical resistance was 36.1 x 10-' ohms/0th.. The modulus of elasticity of the alloy was 22x10 pounds per square inch.

Example II An alloy was prepared containing 60% copper, 20% manganese, and 20% chromium, using high purity metals prepared electrolytically. The alloy,

in the cast condition or when annealed at 750 degrees 0., was soft and ductile and had a tensile strength of approximately 50,000 pounds per square inch. On cold working, it undergoes great work hardening, reaching a tensile strength of about 125,000 pounds per square inch. The electrical resistance of the alloy was 63.7 x 10- ohms/ch13.

As we have indicated hereinabove, we prefer to employ highly pure metals in the preparation of the alloys-of our present invention, the electrolytically produced metals being particularly satisfactory. In the case of manganese, for example, for obtaining the best results in accordance with o'ur present invention, the metal should have a purity of at least 99.0% and preferably a purity of at least 99.9%.

As is clear from the examples, the alloys of our present invention are ductile, are readily worked, and,'as previously stated, have good corrosion resistant properties. The alloys are, therefore,

useful for various purposesin the industrial and engineering fields, illustrative uses being for the manufacture of springs, as electrical resistance wire, for the preparation of decorative articles,

and for other purposes to whichnickel silvers,

Monel metal, and other alloys having ahigh I nickel content are usually put.

What we claim as new and desire to protect by Letters Patent of the United States is:

1. Alloys, having good corrosion resisting properties, containing from 5% to 75% manganese, from 5% to 25% chromium, and 20% to 90% copper, the total of the manganese, chromium, and cop r constituting substantially 100%.

2. Alloys, having good corrosion resisting properties, containing from about 10% to about 20% manganese, from about 10% to about 20% chromium, balance substantially all copper.

3. Alloys, having good corrosion resisting properties, containing from about 5% to about 75% electrolytic manganese, having a purity of at least 99.9%, high purity electrolytic chromium in an amount from 5% to 25%, balance substantially all electrolytic copper of high purity, the copper constituting from 20% to of the a loys.

4. Alloys, having good corrosion resisting prop- 

